Skateboard with steering gear

ABSTRACT

A skateboard with a standing surface for a user and with two wheel axles, on each of which at least two wheels are rotatably mounted, with a mounting for connecting the wheel axles to the standing surface and with steering gears in order to pivot the wheel axles about a vertical axis for steering by tilting the standing surface about its longitudinal axis from a starting position intersecting the longitudinal axis perpendicularly, characterized in that the wheel axles are arranged on the underside of the standing surface.

The invention relates to a skateboard according to the preamble of claim 1.

It is known to manufacture skateboards or skateboards using bearing blocks which at the same time also comprise the steering gear and each have a rubber buffer arrangement in such a way that when the standing board is tilted or inclined about the longitudinal axis to steer the skateboard, the wheel axles swivel in opposite directions about a vertical vertical axis.

EP 0 620 031 B1 discloses a skateboard that comprises a standing board forming a standing surface for a user, with two wheel axles, on each of which at least two wheels are rotatably mounted, and with a holder for connecting the wheel axles to the standing board. The known skateboard has steering gears for pivoting the wheel axles about a vertical axis for steering by tilting the standing board about its longitudinal axis from an initial position intersecting the longitudinal axis perpendicularly; it is further provided that the wheel axles are arranged above the standing board.

It is the object of the invention to create a skateboard which is suitable for riding on plane ground and has a riding dynamic which can be easily influenced by the posture of the user.

This object is solved as stated in claim 1.

The skateboard according to the invention is characterized by a compact and robust construction. Since the wheel axles are provided on the underside of the standing surface, at least the essential elements of the mounting of the respective wheel axle as well as the respective steering gear are also located underneath the standing surface, so that it is particularly suitable for driving on a flat surface such as a road.

Advantageous further embodiments of the invention result from the dependent claims and the description, especially in connection with the drawings.

In an advantageous design, the stand space is formed by two standing boards or alternately by a single standing board covering both wheel axles. When using two standing surfaces, the user stands with each foot on one of the two standing boards and influences the movement of the skateboard with the highest possible precision by his posture and the individual and independent tilting or swivelling of the two standing boards. The more the user tilts the stand boards, the more the skateboard rotates and changes its direction of travel. A connecting rod is mounted in a bearing body under the respective standing board and can rotate freely in relation to the two standing boards. On the other hand, it is possible to support the connecting rod rigidly so that both standing boards together follow the tilting or pivoting movement of the user. A single board covering both wheel axles and common to both feet can preferably be used interchangeably against two separate standing boards. Also, other skateboard components can also be easily exchanged. For example, the choice of wheels can be adapted to the surface on which the skateboard is to be used. The distance between the two stand boards can also be adjusted, for example, according to the length of the user's legs or height.

Preferably, the standing surface is arranged so that it can swivel in relation to each of the wheel axles via swivel joints. Alternatively, a fixing device can be provided to fix each of the two swivel joints.

The swivelling of the two standing boards or the common standing surface can be achieved by using bevel gear transmissions. These preferably have helical gears; by means of the bevel gears the standing surface is converted around the horizontal longitudinal axis of the skateboard into a rotational movement of the skateboard around the vertical axis, which passes through the bevel gears. Instead of helical gears arranged in the manner of a bevel gear, other gear arrangements can also be used.

It is advantageous to limit the pivoting of the skateboard around the longitudinal axis of the skateboard to the range that is usable for rolling, so that the skateboard can be pivoted by an angle of not more than 35°. For this purpose, appropriate stops are provided on the bevel gear teeth.

Thus, in order to be able to use the skateboard for cornering, it is provided that the wheel axles together with a central vertical hub of each of the wheel axes are arranged so that they can rotate relative to the vertical axes of the skateboard hubs and the skateboard contact surface.

Preferably, the wheel axles are arranged so as to be rotatable relative to the vertical axes by an angle of not more than 45° on either side of the skateboard. Preferably, the skateboard has a turning circle with a diameter approximately equal to its length. The maximum rotation of the skateboard about the vertical axes of the standing boards is also determined by stops.

In an advantageous design of the skateboard, the wheel axles are each connected to a vertical hub in their centre, which in turn surrounds the respective vertical axle.

Preferably the wheel axles together with the hubs are each supported around the vertical axle by roller bearings, ball bearings and/or slide bearings.

In another advantageous design, the two swivelling stand boards are connected to each other by means of a connecting rod mounted in slide bearings.

In addition it is provided that the at least one standing board of the skateboard is made up of a plurality of layers, which are loosely laid on top of each other and are jointly fixed by screw or rivet connections to one of the steering gears. This makes it possible to adjust the number of layers individually, or layers of different materials can be used. Polymethyl methacrylate (PMMA) or polyoxymethylene (POM) is preferred. Alternatively, the layers are adhesively bonded to each other, especially glued together. Instead of plastic, wood can also be used, for example in the form of laminated wood.

To support the standing safety of the user, adhesive studs are attached to the at least standing board. These preferably also consist of a hard plastic.

Instead of using gear wheel arrangements, in particular helical gears, the steering gears of the skateboard can also be formed by control cams with inclined planes and cam rollers interacting with them, the cam rollers preferably being provided on the wheel axles.

The skateboard according to the invention is thus optimally suited for riding on level ground, especially on asphalt surfaces, and especially indoors.

Furthermore, transmission ratios can be provided between the bevel gear attached to the bearing block on the underside of the bearing block and designed as a crown wheel and the bevel gear attached to the vertical hub and designed as a pinion in order to influence the driving dynamics. Alternatively, a helical bevel gear can be used in which the axes of the two bevel gears are offset relative to each other; hypoid gears are used here, for example.

In the following, the invention is explained in more detail by embodiments shown in the figures:

FIG. 1 is an isometric view of a first version of a skateboard from above,

FIG. 2 is an isometric view of the skateboard according to FIG. 1 from below,

FIG. 3 shows the skateboard according to FIG. 1 in longitudinal direction,

FIG. 4 shows the skateboard according to FIG. 1 from above,

FIG. 5 shows the skateboard according to FIG. 1 on one end face in a tilted position,

FIG. 6 is a part of the skateboard according to FIG. 5 in isometric view from above,

FIG. 7 is a sectional view of a part of the skateboard according to FIG. 4 along a section line VII-VII,

FIG. 8 is an isometric view of a second version of a skateboard from above,

FIG. 9 is an isometric view of the skateboard as shown in FIG. 8 from below,

FIG. 10 is a partial longitudinal view of a third version of a skateboard with two feet,

FIG. 11 shows the skateboard according to FIG. 10 on one end face,

FIG. 12 is a sectional view of the skateboard according to FIG. 10 along a section line XII-XII,

FIG. 13 shows an isometric partial view from above of a fourth version of a skateboard, which also has two feet,

FIG. 14 a sectional view of the fourth design along a section line corresponding to section line XII-XII of FIG. 10, and

FIG. 15 an isometric view of the skateboard according to FIG. 13 from below.

The skateboard shown in FIGS. 1 to 7 essentially comprises treading or standing boards 1 and 2, which have an essentially circular or elliptical standing surface. In the case of an elliptical standing surface, the major semi-axis of the ellipse extends transversely. In the direction of travel, the two standing boards 1, 2 are connected to each other by a connecting rod 3 which is preferably mounted underneath the standing boards 1, 2 and can be rotated.

Each of the standing boards 1, 2 is attached to a support 4 or 5, respectively, which forms a bearing block and in which the ends of the connecting rod 3 are also mounted. In each of the supports 4, 5 a vertical axis or vertical axle 6 (FIG. 7) is supported. The standing boards 1, 2 are mounted together with the supports 4, 5 so that they can rotate or tilt in relation to the longitudinal axis of the skateboard, which is formed by a pin 7 below each of the standing boards 1, 2. The axis 6 is located in the middle underneath each of the two standing boards 1, 2. By means of a gear, the tilting or pivoting movement of the standing board 1, 2 and the support 4, 5 is coupled with a rotation around the vertical axis 6. The maximum rotation around the vertical axis 6 is given by an angle of for example 45° in relation to the longitudinal direction of the skateboard. The cylindrical pin 7 is supported in a plain bearing 8 in each of the supports 4, 5.

The connecting rod 3 is also supported by a slide bearing 9 in each of supports 4, 5. The connecting rod 3 is connected to the support 4, 5 via a knurled screw 9, which projects into a bead 10 in the connecting rod 3.

Between the support 4 and a hub 11 surrounding the axis 6 there is arranged a pair of intermeshing bevel gears 12, preferably with helical teeth, which allow the base of the standing board 1 together with the support 4 to be swivelled relative to the vertical axis 6, for example by an angle of up to 30°. Depending on the desired riding dynamics of the skateboard, a gear ratio can also be provided between the crown wheel and the pinion of the bevel gear 12. If the quotient of the speed of the ring gear is greater than that of the pinion, its speed is lower than that of the ring gear, but the transmitted torque is greater. The reverse case can also be provided.

The vertically running hub 11 is connected to a horizontal wheel axle 13 and reinforcing brackets 14 to form a supporting frame 15. Two wheels 16, 17 are mounted in the supporting frame 15 so that they can rotate about the wheel axle 13.

The axle 6 is supported in the hub 11 at the level of the wheel hub 13 by a ball bearing 18. Below the bevel wheels 12, the axle 6 is supported in the hub 11 by a roller or ball bearing 13; a roller or ball bearing 19 is used to absorb the weight of the skateboard user.

In addition, plain bearings 20, 21 are provided to support the axle 6 in the hub 11. The bearing of the wheels 16, 17 opposite to the standing board 1 makes it possible to ride the skateboard even in tight curves and at the same time to tilt it according to the centrifugal force, which allows a very fast movement of the skateboard compared to a non-swivelling skateboard. An additional dynamic is ensured by the fact that, due to the pivoting bearing of the connecting rod 3, the two standing boards 1 and 2 can be swivelled individually. The bearings 13, 18, 19, 20, 21 together with the helical bevel gears 12 form the steering gear of the skateboard.

The standing boards 1, 2 each consist of a sequence of several layers 22, 23, 24, for example of a plastic. The layers 22, 23, 24 are connected together by rivets or screws 25 to the support 4 and can be replaced individually. The layers 22 to 24 can also be glued together.

Adhesive studs 25 protrude from the upper layer 22, ensuring good stability for the user on the standing boards 1, 2. Because of the risk of injury, the adhesive studs 25 are preferably made of either plastic or metal; however, they can also be made of a different material.

The support 4 can be closed and encapsulated by a screw 26 to ensure that the pin 7 and the axle 6 are stored free of dirt. This measure also serves the stability of the skateboard.

As an alternative to the design shown in FIGS. 1 to 7, in another design of skateboard only one single standing board 27 (FIGS. 8, 9) is used. The end of the standing board 27 has approximately the same contours as the standing boards 1, 2 and a connecting area 28 in the middle, which for example has a smaller width than end areas 29, 30. Otherwise, the construction of the design as shown in FIGS. 8, 9 is identical to that shown in FIGS. 1 to 7. In this case, connecting rod 3 cannot be rotated. It supports the stability of the skateboard, but can also be omitted, as shown in FIG. 9. Preferably, the stand board 27 can be exchanged for the standing boards 1, 2.

According to another version of the skateboard (FIGS. 10 to 12), it is equipped with a total of eight wheels. Four wheels 31, 32 support the standing board 1 and four wheels 31, 32 support the standing board 2 (not shown). One pair of wheels 31, 32 is each rotatably mounted in a lateral support frame 33 and connected via this to wheel axle 13, which in turn is rotatably arranged around the vertical axis 6 together with supporting frame 15, like wheel axle 13, according to the designs shown in FIGS. 1 to 9. The carrying frame 33 is mounted in the supporting frame 15 around ball bearings, cylindrical bearings, roller bearings 19 or other bearings 34. As explained in the first design example (FIGS. 1 to 7), when the standing boards 1 or 2 are tilted relative to the horizontal, each of the supporting frames 15 performs a rotational movement about the respective vertical axis 6.

Another skateboard has a total of eight wheels in a fourth version (FIGS. 13 to 15) as well as in the third version (FIGS. 10 to 12), of which two pairs of wheels 31, 32 support each of the two standing boards 1, 2, of which only the footprint formed by the standing board 1 is shown in FIGS. 13 to 15. One pair of running wheels 31, 32 are each rotatably mounted in a lateral support frame 35. Via the carrying frame the wheels 31, 32 are connected to the wheel axle 13 and to the supporting frame 15. The wheel axle 13 together with the supporting frame 15 can be rotated around the vertical axle 6 as shown in FIGS. 1 to 12. In contrast to the design example shown in FIGS. 10 to 12, however, the connection between the carrying frame 35 and the wheel axle 13 is rigid because a fixed connection is provided between the carrying frame 35 and the wheel axle 13, for example a bolted connection 36. Even if this reduces the skateboard's mobility compared to the designs shown in FIGS. 1 to 12, the skateboard in this design also performs a rotational movement about the respective vertical axis 6 when the standing surface 1 or 2 is tilted relative to the horizontal of each of the supporting frames 15. This also causes the two pairs of wheels 31, 32 to rotate. 

1. Skateboard with a standing surface for a user and with two wheel axles, on each of which at least two wheels are rotatably mounted, with a mounting or a support for connecting the wheel axles to the standing surface and with steering gears in order to pivot the wheel axles about a vertical axis for steering by tilting the standing surface about its longitudinal axis from a starting position intersecting the longitudinal axis perpendicularly, wherein the wheel axles are arranged on the underside of the standing surface.
 2. Skateboard according to claim 1, wherein the standing surface is formed by two standing boards or, by a single standing board covering both wheel axles.
 3. Skateboard according to claim 1, wherein the standing surface is pivotable relative to each of the wheel axles.
 4. Skateboard according to claim 3, wherein the steering gears comprise bevel gears, by means of which the standing surface is pivotable about the longitudinal axis of the skateboard.
 5. Skateboard according to claim 4, wherein the standing boards can be pivoted through an angle of at most 35°.
 6. Skateboard according to claim 1, wherein the wheel axles together with a central vertical hub each are arranged rotatably relative to the vertical axes of the hubs of the skateboard and the contact surface of the skateboard.
 7. Skateboard according to claim 6, wherein the wheel axles are each arranged so as to be rotatable through an angle of at most 45° to each side with respect to the vertical axles.
 8. Skateboard according to claim 1, wherein the wheel axles are each connected to a hub which in turn surrounds the respective vertical axle.
 9. Skateboard according to claim 8, wherein the hubs are each mounted around the vertical axis via roller bearings, ball bearings and/or slide bearings.
 10. Skateboard according to claim 1, in that the two pivotally mounted standing boards are connected to each other by means of a connecting rod mounted in slide bearings.
 11. Skateboard according to claim 1, wherein the at least one standing board is constructed from a plurality of layers which are laid loosely one on top of the other and are fastened together by screwed or riveted connections with respect to one of the steering gears, or in that the layers are adhesively connected to one another.
 12. Skateboard according to claim 1, wherein adhesive nubs are attached to the at least one standing board.
 13. Skateboard according to claim 1, wherein the steering gears are formed by control cams having inclined planes and cam rollers cooperating therewith.
 14. Skateboard according to claim 1, in that it comprises on each side of the standing boards per axle a pair of wheels, which are each rotatably mounted in a lateral support frame.
 15. Skateboard according to claim 14, in that the lateral support frames are rotatably mounted on a supporting frame mounted about the central vertical axis or in that the lateral support frames are rigidly mounted on the supporting frame mounted about the central axis. 